This invention relates to a machine for forming round bales of forage crops and, more particularly, to apparatus for wrapping a strand of binding twine in coiled fashion around a round bale between the opposite ends thereof, said apparatus having mechanism to effect roving of the binding twine around said bale as the bale is being rotated around a horizontal axis prior to discharging the same from the bale forming machine.
It has been the accepted and customary way to harvest and store forage crops for many years by mowing the crop in the field, permitting it to dry to a reasonable extent, forming it into windrows, and compacting the windrows into rectangular shapes of bales by conventional hay-baling machines of customary type. To store rectangular type bales, they must either be conveyed to a shed or barn and stacked, or if they are left in the field, they must be covered with waterproof coverings in order to provide means for shedding rain and other types of moisture in order to prevent the bales from rotting.
In recent years, an innovation has occured in the baling art in the form of machine which handles the windrows in a manner to coil the same into a relatively compact roll, usually of very substantial size and weighing many hundreds of pounds such as of the order of between 1000 and 1500 pounds. One of the principal advantages of roll type bales of forage crops is that they may be much more readily stored as well as fed to herbivorous animals simply by letting the rolls lie on one side in a field or feed lot. In this condition, animals may readily feed upon such rolls until they are gradually consumed. In order to stabilize the rolls, it has become accepted practice to coil a strand of binding twine or the like circumferentially around the rolls and extend the same somewhat in spiral manner between opposite ends of the roll.
For purpose of illustrating typical types of machines for forming round bales, attention is directed to U.S. Pat. No. 3,815,345 that discloses a machine that has been highly succesful in the formation of round bales. Also, for purposes of illustrating a typical type of apparatus for disposing a roving type strand of binding twine in spiral manner around a round bale, attention is directed to U.S. Pat. No. 3,910,178, to Eggers et al., and assigned to the assignee of the instant invention. In the latter machine, the application of the binding twine to the roll is at least in part effected manually by an operator sitting, for example, upon the seat of the tractor which propels the round bale forming machine along a field.
In addition to the aforementioned prior art patents, reference is also made to U.S. Pat. No. 3,913,473, to Meiers, dated Oct. 21, 1975 and in which roving of the binding twine is effected by hydrauically-acted mechanism which moves a twine directing arm substantially along a horizontal plane while distributing the twine from the outer end of the arm which moves in an arcuate path between opposite sides of the bale forming machine.
One problem encountered in previously employed devices for applying a substantially spiral type strand of binding twine around a round bale of forage crop materials has been the inability to furnish adequate tension to the twine as it is applied to the bale and particularly to achieve substantially even tension in the twine between opposite ends of the bale. Further, in manually operated twine applying devices, it has been found that when tractors, for example, of substantial horsepower and large size are employed to propel a round bale forming machine along a field, the seat for the operator either is enclosed within a cab or otherwise is sufficiently remote from the bale forming machine that it is difficult or even impossible for the operator to negotiate operation of manually operated means to effect the deployment of the binding twine around a round bale as produced in a round bale forming machine.